# Question #24b9d

Feb 22, 2016

The orbital period is more than 5.58 million years, nearly. It would be close to us once in this period.

#### Explanation:

The formula for the period of a solar orbiter is $T = \left(2 \pi\right) {\left(a\right)}^{\frac{3}{2}} / \sqrt{\mu}$.

For the Earth, a = 1 AU and T = 1 year. For these units of distance and period, $\sqrt{\mu} = 2 \pi$..

So, if the semi-major axis a is in AU unit and the time unit is Earth year, the period is nearly a$\sqrt{a}$ years

1 light year is nearly 62900 AU.

The orbit eccentricity for such a comet will be very close to 1.
Assuming that aphelion is 1 ly = a( 1 + e ) = 2a, nearly, a = 0.5 ly = 31450 AU nearly,

Compared to aphelion, perihelion will be very small and will be too small, if the eccentricity is too close to 1. So, the chance of acquiring very high perihelion speed and shedding mass for meteors to enter our atmosphere is more, when it braces our atmosphere.

For this a, period is .$31450 \sqrt{31450}$ years= 5.58 million AU, nearly.

Such a comet could possibly come very close to both the Earth and the Sun, once in 5.58 million years, nearly. .. .